Category: Industry Trends

Boiler design

The Aalborg D features a compact, vertical “D”-shaped

configuration with interconnected steam and water drums.

Its furnace is built with fully water-cooled membrane walls and

minimal refractory, ensuring durability and safety in harsh offshore

environments. The convection section uses straight pin tubes with

bent pins for high heat transfer and low pressure loss.

Reliable water circulation is maintained by external downcomers,

preventing overheating and tube burnout.

Integrated Burner Technology

Alfa Laval’s Gosfern® dual-fuel burners offer maximum flexibility

and efficiency for offshore use. They operate with a wide range

of liquid and gas fuels and can fire both simultaneously, ensuring

seamless fuel switching and reliable operation.

Precisely integrated with the Aalborg D furnace, these burners

deliver stable combustion, low emissions, and consistent

performance—even under changing load conditions. This robust

technology supports environmental compliance and operational

efficiency, making it ideal for offshore environments.

Advanced control systems maintain stable steam pressure and

high steam quality, while hot water heater operation is managed

by precise temperature control.

Capacity range

With steam capacities ranging from 45 to 130 t/h and hot water

outputs up to 90 MWth, the Aalborg D ensures reliable, efficient,

and flexible performance to meet the demanding requirements of

offshore applications.

Key Features

• Flexible production of both steam and hot water to meet

diverse offshore needs

• High-capacity output: up to 130 t/h steam or 90 MWth hot

water

• Robust design pressure up to 48 bar(g) for demanding

operations

• Superheated steam available up to 415 °C

• Versatile multi-fuel capability

• Efficient, integrated multi-burner system with minimal

refractory requirements

• Engineered for both indoor and outdoor use, including

hazardous area compliance

• Comprehensive auxiliary systems available, such as

combustion skids, gas valve units, and feedwater solutions

• Delivered as modular packages or loose components for

flexible installation

Key benefits of choosing the Aalborg D Multi-fuel boiler

• Robust control system architecture supports reliable,

continuous operation.

• Pressure part designed with natural circulation for high

availability and operational resilience.

• High steam quality for power generation and/or process

utility steam

• High thermal efficiency exceeding 85% without the need of

exhaust gas economizers ensuring lower CAPEX

• Optional economizer for optimal thermal efficiencies

exceeding 95% ensuring lower OPEX

• Designed with low-NOx burners, using air/fuel staging

technology

• Designed using flue gas re-circulation to achieve lower NOx

operation in accordance with industry standards.

• Combustion system suitable for wide range of fuels – both

gaseous and liquid – from standard marine fuels to various

offshore crude qualities in addition to volatile organic

compound gases with reduced heating values

Aalborg D Multi-fuel boiler with top-fired burner technology

for Offshore applications

Introduction

The Alfa Laval Aalborg D Multi-fuel is a high-performance oil- and

gas-fired boiler engineered for the demanding conditions of the

offshore industry. Featuring advanced top-fired burner technology,

it delivers optimal combustion and flexibility, supporting both steam

and air atomization for reliable operation.

Designed to operate efficiently with a wide range of fuels, including

MGO, MDO, LNG, VOC gas, HFO, LFO, liquid condensate, and

crude oil, the Aalborg D adapts seamlessly to your fuel supply and

operational needs.

Available as a saturated steam boiler, superheated steam boiler, or

hot water heater, it is ideal for service steam, power generation, and

heat exchange applications offshore.

The Aalborg D’s multi-fuel, multi-burner configuration allows

burners to operate simultaneously on gas and liquid fuels, as well

as dual-fuel firing across various load ranges using advanced

combustion techniques. Integrated flue gas recirculation and

air/fuel staging reduce NOx emissions, ensuring compliance

with international emissions standards and supporting your

sustainability targets.

The Alfa Laval Aalborg D is a large-capacity marine boiler for producing

steam or hot water, especially on tankers. Fired with oil or gas, it has a

D-type design, in which the steam drum and water drum are connected

by a generating tube bank. The boiler’s furnace, which contains little

refractory, has membrane walls with external downcomers that promote

effective circulation. Delivered as a complete unit, the Aalborg D has a

steam capacity range of 25–120 t/h and a design pressure of 18 bar(g).

Large-capacity fired boiler with proven design

• Match your capacity needs with standard boiler sizes, delivered as

complete units for easy installation

• Configure for oil or gas as fuel, changing no more than the burner

• Produce steam with high efficiency and natural water circulation

Aalborg D is a standard vertical two-drum boiler. The furnace is built of

membrane walls and contains a minimum of refrac tory. The convection

section consists of straight pin tubes with bent pins that provide a high

heat transfer coefficient and low pressure loss. Circulation is ensured by

downcomers arranged outside the furnace.

Capacity range: 25 – 120 t/h

Aalborg 3-Pass is an oil and gas-fired industrial boiler, which is designed and optimised

with the total of Alfa Laval’s technical and innovative competencies in every detail – inside out.

Industries

Oil and Gas

Oil and gas operations are all about constantly optimizing process performance while

maintaining safety for people and the environment.

Renewable power

Renewable power generation promotes sustainable development through a sound and

secure energy supply. Alfa Laval’s expertise, equipment and services contribute to a

low-carbon energy future.

Thermal power

Increasing efficiency and reliability calls for broad expertise, technologies and services.

Alfa Laval’s solutions for turbine-driven power plants help secure stable, economical supply

of electricity.

Design data

• Heat capacity:1.5 – 25.5 MW

• Steam capacity: 2.0 – 39 t/h

• Design pressure:up to 20.7 bar g

• Steam temperature:Saturated

• Efficiency (DIN 1942):91-95%

A thoroughly industrial design based on recognized and well proven principles.

Utilizing the latest technology, the boiler is optimized to assure quality, reliability,

long life, easy maintenance and sound economy.

Technical data

Aalborg CHB boilers offer capacities ranging from 0.75 to 8 t/h. Standard design pressure

is between 10 and 18 bar(g), with thermal output up to 6 MW.  Several capacities and

dimensions available for the standard product range.

Options

In addition to the standard configuration features, the Aalborg CHB can be equipped with

a wide range of optional accessories according to a specific vessel’s needs. 

These include:

• Flue gas economizer

• For optimized performance and fuel savings, boiler can be equipped with external flue gas

economizer to further improve thermal efficiency.

• Electrical heating elements

• For emission-free port operation, electric heating elements can be integrated to provide

steam while the vessel is connected to shore power.

• Water Chemistry Solution

• Ensuring the long life cycle of steam generation system equipment and maintaining

operational reliability.

• Pressurized deaerator

A pressurized deaerator ensures optimal feedwater quality by thermally degassing dissolved

oxygen and other non-condensable gases. This significantly reduces corrosion risk and improves

the reliability and longevity of the boiler system.

How it works

Standard configuration

The Aalborg CHB design consists of a large furnace welded to vertical, plain-type convection

tubes with spiral inserts. The low-alloyed plate material is easy to weld and is highly durable

to prevent cracking. Aalborg CHB boilers have fully water-cooled furnaces and can be

equipped with various burner types. The boiler comes complete with connections, foundation,

inspection hatches, manhole, hand-holes, insulation with sheeting as well as all valves and fittings.

Other standard features include:

• Modulating boiler water regulation

• Burner type according to preference and the type of fuel used

• Alfa Laval Gas Valve Units (GVU) and Methanol valve units (MVU) for alternative fuels

• Processor-based control system

• Control panel with touchscreen interface for all necessary operation, communication,

safety and alarm functions

• Integrated water-washing device

• Spare parts according to classification society demands

Standard configuration

The Aalborg CHB design consists of a large furnace welded

to vertical, plain-type convection tubes with spiral inserts. The

low-alloyed plate material is easy to weld and is highly durable to

prevent cracking.

Aalborg CHB boilers have fully water-cooled furnaces and can be

equipped with various burner types. The boiler comes complete

with connections, foundation, inspection hatches, manhole, hand

holes, insulation with sheeting as well as all valves and fittings.

Other standard features include:

• Modulating boiler water regulation

• Burner type according to preference and the type of fuel used

• Alfa Laval Gas valve units (GVU) and Methanol valve units

(MVU) for alternative fuels

• Processor-based control system

• Control panel with touchscreen interface for all necessary

operation, communication, safety and alarm functions

• Spare parts according to classification society demands

A pressurized deaerator ensures optimal feedwater quality

by thermally degassing dissolved oxygen and other non

condensable gases. This significantly reduces corrosion risk

and improves the reliability and longevity of the boiler system.

Technical data

Aalborg CHB boilers offer capacities ranging from 0.75 to 8 t/h.

Standard design pressure is between 10 and 18 bar(g), with

thermal output up to 6 MW. The table below shows capacities

and dimensions for the standard product range.

Benefits

The Aalborg CHB is a highly efficient boiler, with an efficiency level

of up to 89% at nominal load. With a number of advanced design

features, the boiler provides several important benefits for ship

owners and operators:

• Reduced fuel consumption with corresponding reduction in

vessel operating costs

• Decreased CO2 and NOx emission levels

• Good combustion due to proper furnace dimensioning

• Moderate loading and low material stresses

• Minimal refractory with water-cooled furnace bottom

Options

In addition to the standard configuration features, Aalborg CHB

can be equipped with a wide range of optional accessories

according to a specific vessel’s needs. These include:

• Flue gas economizer

For optimized performance and fuel savings, boiler can

be equipped with external flue gas economizer to further

improve thermal efficiency.

• Electrical heating elements

For emission-free port operation, electric heating elements

can be integrated to provide steam while the vessel is

connected to shore power.

• Water Chemistry Solution

Ensuring the long life cycle of steam generation system

equipment and maintaining operational reliability.

• Pressurized deaerator